Bitstream generation tools for bitstream management system

ABSTRACT

An apparatus comprising a first tool configured to generate one or more parameter signals in response to (i) one or more control signals and (ii) an input signal and a second tool configured to generate one or more edited bitstreams in response to (i) one or more bitstreams and (ii) the one or more parameter signals.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application may relate to co-pending application Ser. No.08/838,798, which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present invention relates to bitstream management systemsgenerally and, more particularly, to a bitstream corruption/compressiontool for a bitstream management system.

BACKGROUND OF THE INVENTION

[0003] Bitstreams are common in digital video and digital audio issystems. Corrupted bitstreams are used to uncover problems in thedesigns, such as lockup conditions. In the past, specific bitstreamstructure corruption tools have been used. However, such tools arelimited in capability and applicability. An example of a specificbitstream corruption tool is the tool used to corrupt an audio frameadequately to generate a CRC error signal.

[0004] The disadvantage with such a tool is specific use constrainslimit re-use applicability. For example, hard coding based on abitstream specific structure makes it more difficult to re-use the tool.Additionally, advanced features such as protection of fields fromcorruption, are not supported with such tools.

[0005] Other stand-alone tools for bitstream corruption require the userto specify the tool parameters. Such parameter specification istypically not efficient, since such programming can be a tedious,arduous, process requiring review of what fields should be corrupted andwhat fields should be protected from corruption. Such a selectionprocess must be repeated on each pass for each bitstream available forcorruption.

[0006] The disadvantage with such an approach is the lack of automationof corrupted bitstream generation based on bitstream characterizationreports. The lack of higher level constructs to instruct the use of thebitstream corruption tool is another disadvantage.

[0007] Additionally, existing bitstreams generated by such corruptiontools are used for regressions, without incorporating compactionconcepts. Such uncompressed bitstreams, corrupt or not, create a lengthyprocess of verification, since the huge bitstreams require large amountsof time and CPU resources to run.

[0008] The disadvantage with such an approach is that it fails toprovide (i) compression or compaction of the generated bitstreams, (ii)small, high coverage, bitstreams, and (iii) higher level constructs tocreate dense bitstreams.

SUMMARY OF THE INVENTION

[0009] The present invention concerns an apparatus comprising a firsttool configured to generate one or more parameter signals in response to(i) one or more control signals and (ii) an input signal and a secondtool configured to generate one or more edited bitstreams in response to(i) one or more bitstreams and (ii) the one or more parameter signals.

[0010] The objects, features and advantages of the present inventioninclude providing a programmable bitstream compression/corruption toolthat may (i) be used on a variety of bitstreams for a variety ofcorruption needs, (ii) provide a full spectrum of corruption rangingfrom full random corruption to field occurrence specific corruption,and/or (iii) provide corruption at different rates within a particularbitstream.

[0011] One aspect of the present invention includes providing a testingand verification system that may (i) automatically generate usefulcorrupted bitstreams, and/or (ii) specify fields in a bitstream to havespecific levels of corruption based on the bitstream characterizationreports, such as bitstream management system (BMS) reports.

[0012] Another aspect of the present invention includes providing asystem that may (i) automatically generating useful, high coverage (upto comprehensive), compact bitstreams, (ii) rile provide self-assessmentof syntax compliance and coverage of particular bitstream sets, (iii)provide bitstream compaction of existing bitstream(s) down to theessence of the coverage of the original bitstream, and/or (iv) generatecompact, high coverage bitstreams (e.g., down to the field level).

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] These and other objects, features and advantages of the presentinvention will be apparent from the following detailed description andthe appended claims and drawings in which:

[0014]FIG. 1 illustrates an example of a portion of a bitstream that maybe used with the present invention;

[0015]FIG. 2 illustrates a block diagram of a preferred embodiment ofthe present invention;

[0016]FIG. 3 illustrates a more detailed block diagram of thecorruption/compression tool of the present invention;

[0017]FIG. 4 illustrates a block diagram of an alternate embodiment ofthe present invention; and

[0018]FIG. 5 illustrates an alternate embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The present invention may provide a programmablecorruption/compression tool and method for using the tool. The presentinvention may enable a wide range of bitstream corruption/compression.The present invention may add significantly to the design verificationtechniques and capabilities needed to achieve comprehensive verificationtime to market and time to volume windows.

[0020] Referring to FIG. 1, an example of a bitstream 50 used in thepresent invention is shown. The bitstream 50 generally comprises a startcode portion 52, a header portion 54 and a payload section 56.

[0021] Referring to FIG. 2, a block diagram of a tool 70 is shownimplementing a preferred embodiment of the present invention. In apreferred embodiment, the tool 70 may be implemented in software.Alternately, the tool 70 may be implemented as a hardware device. Onesoftware implementation of the present invention may be in an electroniccomputer aided design (ECAD) system. However, other systems may be usedaccordingly to meet the design criteria of a particular implementation.The tool 70 generally comprises a number of inputs 72 a-72 n, an input74, an input 76 and an output 78. The input 74 may receive a bitstream(e.g., BS). The inputs 72 a-72 n may receive one or more of reports thatmay provide information about the bitstream BS. The input 76 may receivea control signal (e.g., USER.INPUT). The output 78 may present an editedbitstream (e.g., EDITED_BS ). The edited bitstream EDITED_BS may be analtered version of the bitstream BS received at the input 74. The editedbitstream EDITED_BS presented at the output 78 may be (i) a corruptedversion of the bitstream received at the input 74, (ii) a compressedversion of the bitstream received at the input 74 or (iii) a combinationof an edited bitstream and a corrupt bitstream received at the input 74.Additionally, the edited bitstream EDITED_BS may have one or more typesof corruption and/or one or more types of compression.

[0022] Referring to FIG. 3, a more detailed diagram of the tool 70 isshown. The tool 70 generally comprises a parameter tool 80 and aprocessor tool 82. The parameter file generator tool may generate asignal (e.g., PARAMETER) and an output 84 that may be presented to aninput 86 of the processor tool 82. The processor tool may generate theedited bitstream BITSTREAM_BS at the output 78 in response to the signalPARAMETER, the bitstream BS and the signal USER.INPUT.

[0023] Referring to FIG. 4, a block diagram of a circuit (or tool) 100is shown implementing an example of the present invention. The tool 100may be a bitstream corruption tool. The tool 100 generally comprises atool (or circuit) 102, a tool (or circuit) 104 and a tool (or circuit)106. The tool 106 may be an output/processes tool. The tool 104 may be afile generator tool. The tool 102 may be a bitstream management softwaresystem, such as that found in co-pending application Ser. No.08/838,798, which is hereby incorporated by reference in its entirety.

[0024] The bitstream management software tool 102 generally comprises ablock (or circuit) 110, a block (or circuit) 112, a block (or circuit)114, a block (or circuit) 115, a block (or circuit) 116, a block (orcircuit) 118 and a block (or circuit) 120. The block 110 may receive anexisting bitstream. The block 112 may receive a static bitstream. Theblock 114 may receive a variable permutation of the bitstream. The block115 may be a bitstream profile block.

[0025] The bitstream profile block 115 generally receives signals fromthe block 110, the block 112 and the block 114 and generally presentsthe signals to a block 116, the block 118 and the block 120. The block116 generally presents the bitstreams at an output 117.

[0026] The block 116 may be a bitstream generation block. The block 118may be a bitstream checking block. The block 120 may be a collectivecoverage block. The bitstream management system 102 may have an output130, an output 132 and an output 134. The output 130 may present asignal (e.g., PROFILE.REPORT) to an input 140 of the file generatorblock 104. The output 132 may present a signal (e.g., CHKING.REPORT) toan input 142 of the file generator 104. The output 134 may present asignal (e.g., COVERAGE.REPORT) to an input 144 of the file generator104. A signal (e.g., USER_INPUT may be presented to an input 146 of thefile generator 104). The file generator 104 may present a signal (e.g.,GCORR_BS_PARAMETER_FILES) at an output 150. The signalGCORR_BS_PARAMETER_FILES may be received at an input 152 of theoutput/processes block 106. The bitstreams may be presented to an input154 of the output/processes block 106. The output/processes block 106may present the corrupted bitstreams at an output 156 in response to thebitstreams received at the input 154 and the signalsGCORR_BS_PARAMETER_FILES.

[0027] The following syntax illustrates an example of a softwareimplementation of the present invention: gcorr_bs fname every_xBcorrupt_yB #_of_fields_to_corr #_of_fields_to_protectcorr_fields_location corr_fields_size corr_fields_freqcorr_fields_occurrences prot_fields_location prot_fields_sizeprot_fields_freq prot_fields_occurrences.

[0028] The command gcorr_bs may be a command to call (e.g., beginexecution) the tool. The command fname may be the filename of the inputbitstream. The command(s) every_xB, every x bytes may specify the rangeof the bitstreams. The value x generally needs to be between 0 and themaximum bytes in the input bitstream. The command(s) corrupt_yB, corrupty bytes may specify the level of corruption of the bitstreams. For everyx bytes, corrupt y bytes. In one example, every_xB/corrupt_yB may beless than 8 for reasonable corrupted bitstreams that still enablepartial operation of the unit under test. The command#_of_fields_to_corr generally defines the number of field(s) to corrupt.The command #_of_fields_to_protect generally defines the number offield(s) to protect.

[0029] The command corr_fields_location generally defines the locationof the field(s) to corrupt. The command corr_fields_size generallydefines the size of the field(s) to corrupt. The commandcorr_fields_freq generally defines the frequency of the field(s) tocorrupt. The command corr_fields_occurrences generally defines thenumber of occurrences of the field(s) to corrupt. The commandprot_fields_location generally defines the location of the field(s) toprotect. The command prot_fields_size generally defines the size of thefield(s) to protect. The command prot_fields_freq generally defines thefield to protect frequency. The command prot_fields_occurrencesgenerally defines the field to protect occurrences.

[0030] A specific implementation of the present invention may beillustrated by the following example: gcorr_bs in.bs 64 8. Thisimplementation would corrupt a bitstream called in.bs on average 8 bytesout of every 64 bytes.

[0031] Another implementation of the present invention may beillustrated by the following example: gcorr_bs in.bs 32 4 1 0 1024 11024 all. This would corrupt a bitstream called in.bs on average 4 bytesevery 32 bytes of the 1 byte field that occurs every 1024 bytes.

[0032] Another implementation of the present invention may beillustrated by the following example: gcorr_bs in.bs 64 4 0 1 0 0 0 02048 4 0 1. This would corrupt a bitstream called in.bs on average 4bytes every 64 bytes except for the 4 byte field that starts at 2048(this would not be corrupted).

[0033] Another implementation of the present invention may beillustrated by the following example: gcorr_bs in.bs 64 5 2 0 512 4 10246 580 3 1024 7. This would corrupt a bitstream called in.bs on average 5bytes every 64 bytes in 6 occurrences of the first field that is 4 bytesin size and occurs at 512 and repeats at 1024, and in 7 occurrences ofthe second field that is 3 bytes in size and occurs at 580 and repeatsat 1024.

[0034] The above examples are illustrative of the operation of thepresent invention. A wide variety of specific examples may beimplemented to meet the design criteria of a particular application. Forexample, the present invention may provide a single tool for allbitstream corruption needs. A range of tool parameters that can beeasily generated from other processes may also be supported. Fullprogrammability for multiple field corruptions and protections may alsobe supported.

[0035] Multiple applications of the tool 100 may be run on subsequentprocesses on the bitstream. Such multiple applications may providelayers of corruption and protection of fields where the corruption mayoperate on different fields. Particular data payloads may be capable ofsustaining very high rates of corruption, where the header syntax startcode may need a small rate of corruption and the rest of the syntax mayneed a mild rate of corruption.

[0036] A portion of the features of the present invention may beimplemented on a particular portion of the bitstream. For example,protection of fields may be programmable with the present inventionwithout additional modification, such as corruption.

[0037] Bitstream corruption is a necessary part of design verificationof digital audio and video systems. The present invention may provideadvanced features and usage methodology that may be used to save monthsin design verification work by providing a convenient system forstressing the systems' and sub-systems' capabilities in a programmableand systematic way in a short amount of time.

[0038] Another aspect of the present invention may provide automation ofthe features of the bitstream corruption tool 100. 0l Automation of thepresent invention may leverage information available in BMS reports. Anexample of BMS reports may be found in the Bitstream Management Systemdescribed in co-pending application Ser. No. 08/838,798, which is herebyincorporated by reference in its entirety. However, other bitstreammanagement systems may be implemented accordingly to meet the designcriteria of a particular implementation.

[0039] A BMS profile is generally a readable condensed version of thebitstream that can distinguish fields in the bitstream. A BMS checkingreport may specify, down to the field level, illegal portions of thebitstreams that have been run. A BMS coverage report may specify, downto the field level, what has not been covered (in terms of possiblepermutations) in the bitstreams that have been run. The BMS profile, theBMS checking report and the BMS coverage report may be generated by thebitstream management software.

[0040] The BMS profile, the BMS checking report and the BMS coveragereport may provide input that may be used to specify the parameters forthe sets of uses for the bitstream corruption tool 100. The BMS profile,the BMS checking report and the BMS coverage report may represent asingle bitstream or many bitstreams.

[0041] The present invention may use user input on the desiredcorruption process to produce the corrupted bitstream sets to be usedfor verification. The BMS would have run the bitstream candidates forcorruption through profiling, checking and coverage tools. Thesereports, along with optional user input, may be used to produce thecorrupted bitstream set(s).

[0042] An example of the user input may be one or more of the following:(i) corrupt fields in profile, (ii) corrupt fields not in profile, (iii)corrupt legal fields in checking report, (iv) corrupt illegal fields inchecking report, (v) corrupt fields in coverage report, (vi) corruptfields not in coverage report (this means the fields have not beencomprehensively covered), (vii) corrupt fields not in profile and not incoverage report, (viii) corrupt fields not in profile and illegal fieldsin checking report corrupt fields not in profile, illegal field inchecking report and not in coverage report, (ix) corrupt illegal fieldsin checking report and not in coverage report, (x) corrupt all fields inprofile, checking and coverage reports, (xi) corrupt start code field inprofile at 16/1, rest of header syntax at 16/4 and all data payload at64/32, (xii) corrupt fields not in coverage report with start code fieldin profile at 10/1, rest of header syntax at 10/3 and all payload at64/64, and (xiii) corrupt fields in profile at 64/8, except for illegalfields in checking report which should be at 32/4. The user may provideinput that may be used to specify which fields in the profile shouldhave a particular level of corruption.

[0043] In the example below, the BMS coverage report may be processed toassess what fields are not covered. The bitstream is then corrupted inthe fields that are not covered. The following example illustrates whena user has run a single bitstream through BMS profiler, checking andcoverage tools and has reports from the tools. The user wants ‘corruptfields not in coverage report’.

[0044] The circuit 100 generates (e.g., from coverage report) whatfields were not covered, and builds parameter file for gcorr_bs tool.Then, the gcorr_bs tool is run with the output being the corruptedbitstream that meets the specified requirements. In the above example,the file gcorr_bs may be received from the bitstream generation block116, where

[0045] >gcorr_bs in.bs 64 5 2 0 512 4 1024 6

[0046] 580 3 1024 7

[0047] Such an example would corrupt a bitstream called in.bs (i) onaverage 5 bytes every 64 bytes in 6 occurrences of the first field thatis 4 bytes in size and occurs at 512 and repeats at 1024, and (ii) in 7occurrences of the second field that is 3 bytes in size and occurs at580 and repeats at 1024.

[0048] The present invention may be used as automated system forcreating generic or custom corrupted bitstreams based on user input andexisting reports on the makeup of the bitstream(s). The user inputoptions may be verbose and may include options for specifying thecorruption at various levels in various bitstreams. Higher levelconstructs may be used to specify what should be corrupted in theparticular bitstream(s).

[0049] Particular aspects of the circuit 100 may be independentlyimplemented. For example, an option may be implemented to allow the userto specifying what fields should have what level of corruption in agroup of bitstreams and automatically having the corrupted bitstreamsgenerated may be implemented.

[0050] Bitstream corruption is a necessary part of design verificationof digital audio and video systems. The present invention provides aclosed loop, automated system, for generating useful corruptedbitstreams to be used in verification using higher level constructs. Forexample, the user can input the higher level construct ‘corrupt fieldsnot in coverage report’, and the system will instantly produce thecorrupted bitstreams that stress the audio or video system (orsub-system) without needing to craft other bitstreams to complete fieldcoverage. The present invention may provide a productivity improvementthat may be reflected in schedules improved by weeks on largedevelopment.

[0051] The present invention may also enable generation of compact highcoverage bitstreams. Referring to FIG. 5, a circuit 100′ is shownillustrating an alternate embodiment of the present invention. Thecircuit 100′ modifies the bitstream management software circuit 102′ andthe generator circuit 104′. The bitstream profile circuit 115′ may beconfigured to receive an edited bitstream profile at an input 164. Theedited bitstream profile may be received from the output 150′ of thegenerator circuit 104′. The edited profile may also be presented to aninput 162 of the bitstream generation block 116′. An output 160 of thebitstream generation circuit 116′ may present a compacted bitstream(e.g., COMPACTED_BS ). The BMS profiling function constructs a profilefrom an existing bitstream. The profile may be a readable condensedversion of the bitstream that can distinguish fields in the bitstream.The BMS Bitstream Generation function may generate a bitstream based onthe profile (which may have been edited since constructed). The BMSchecking function may generate a report down to the field level on whatis illegal in the bitstream(s). The BMS coverage report function maygenerate a report down to the field level on what has not been covered(in terms of possible permutations) in the bitstream(s).

[0052] The compact bitstream generation process may be implemented withall of the BMS functions. Examples of three user input choices will bepresented in detail: (i) creating compact existing bitstreams, (ii)creating compact bitstream for verification of field x and (iii)creating compact bitstream for comprehensive coverage.

[0053] The compression aspect of the present invention may review theprofiles of the existing bitstreams. A single profile is generallydeveloped based on the bitstream profile reviews that generallyrepresents a significant compaction.

[0054] The bitstream generator 104′ may generate a bitstream based onthe bitstream profile. The generated bitstream may be run through thechecking and coverage tools to ensure the goals have been met (e.g., thesame level of compliance and coverage as the existing bitstreams). Ifnot, the profile may be refined to achieve the desired compliance.

[0055] An option may be implemented to ignore data size and value thatmay dramatically reduce the size of the bitstreams. A compact bitstreammay be created for verification of field(s). The field must generally bespecified in the same manner it is represented in the profile. The fieldcoverage may not always be reasonable for audio or video experience, butwill be legal and leverage existing coverage and, in large part, beuseful in verification.

[0056] The profiles of the existing bitstreams may now be reviewed. Asingle profile is generally copied from an existing one and edited toadd the field x coverage. The bitstream generation function generates abitstream based on this single profile.

[0057] The generated bitstream is run through the checking and coveragetools to ensure the goals have been met (the level of compliance andcoverage desired). If not, the profile is refined to achieve this.

[0058] An option may be implemented to create compact bitstream forcomprehensive coverage.

[0059] A profile must exist to represent the bitstream fields to cover.

[0060] The coverage bitstream generated may not always be reasonable foraudio or video experience, but will be legal and leverage existingcoverage information, and in large part, be useful in verification withthe various syntax permutations covered.

[0061] The profiles of the existing bitstreams are reviewed. A singleprofile is copied from an existing one and edited to add full coverage.The bitstream generation function generates a bitstream based on thissingle profile. The generated bitstream is run through the checking andcoverage tools to ensure the goals have been met (the level ofcompliance and coverage desired). If not, the profile is refined toachieve this.

[0062] The present invention may provide (i) an automated system forcreating compact bitstreams from existing bitstreams that substantiallyachieves the same level of coverage as the existing bitstreams, (ii) anautomated system for creating compact bitstreams to achieve the desiredcoverage level of specific or all fields, and/or (iii) implement higherlevel constructs that may be used to specify compaction.

[0063] Part of the invention may be implemented on particularbitstreams, like compacting existing bitstreams, ignoring data size andvalue. For example, 250 Mytes could be reduced to one MByte, saving muchtime in development.

[0064] Bitstreams used in design verification of audio and video digitalsystems can be huge. This invention provides a system and methodology tocompact large bitstreams and craft other compact bitstreams toaccelerate design verification. The user may run all the legacybitstreams for verification and on the next pass of the design run acompact bitstream to reduce the regression run time. This can save weekson a large development.

[0065] While the invention has been particularly shown and describedwith reference to the preferred embodiments thereof, it will beunderstood by those skilled in the art that various changes in form anddetails may be made without departing from the spirit and scope of theinvention.

1. An apparatus comprising: a first tool configured to generate one ormore parameter signals in response to (i) one or more control signalsand (ii) an input signal; and a second tool configured to generate oneor more edited bitstreams in response to (i) one or more inputbitstreams and (ii) said one or more parameter signals.
 2. The apparatusaccording to claim 1, wherein said one or more control signals compriseone or more bitstream reports.
 3. The apparatus according to claim 1,wherein said one or more parameter signals are automatically generatedin response to (i) said one or more control signals and (ii) said inputsignal.
 4. The apparatus according to claim 1, wherein said one or moreedited bitstreams are corrupted versions of said one or more inputbitstreams.
 5. The apparatus according to claim 1, wherein said one ormore edited bitstreams are compressed versions of said one or more inputbitstreams.
 6. The apparatus according to claim 1, wherein said one ormore edited bitstreams are corrupted and compressed versions of said oneor more input bitstreams.
 7. A method of modifying one or morebitstreams comprising: (A) entering a specification for a desiredbitstream edit; and (B) executing the operation of the desired bitstreamedit in response to a control signal to generate an edited bitstream. 8.The method according to claim 7, further comprising the step of: (C)measuring the result of step (B).
 9. The method according to claim 7,further comprising the step of: (D) automating step (B).
 10. The methodaccording to claim 7, wherein the specification for the edit is forcorruption having a number of specification options included where: (A)one or more options for corruption are selected from the groupconsisting of: (i) every x bytes, corrupt y bytes; (ii) the number offields to corrupt; (iii) the number of fields to protect; (iv) the fieldto corrupt location affiliated with (a) the field to corrupt size, (b)the field to corrupt frequency, and (c) the field to corruptoccurrences; (v) a field to protect location affiliated with (a) thefield to protect size, (b) the field to protect frequency, and (c) thefield to protect occurrences; and (vi) a field to protect locationaffiliated with (a) the field to protect size, (b) the field to protectfrequency, and (c) the field to protect occurrences.
 11. The methodaccording to claim 10, wherein other processes select the specificationoptions and the values for the options.
 12. The method according toclaim 11, wherein said specification options for corruption include (i)any number of sets of fields to corrupt, and (ii) any number of sets offields to protect.
 13. The method according to claim 10, wherein themethod is used multiple times on the same bitstream with the samespecification to produce one or more different edited corrupt and/orcompact bitstreams.
 14. The method according to claim 10, wherein themethod is used multiple times on the same bitstream with differentspecifications such that different corruption rates are supported fordifferent field(s) of the bitstream.
 15. The method according to claim10, wherein the corruption can be random or deterministic of thespecified fields to be corrupted.
 16. The method according to claim 10,used in a system that automates the corruption of said one or morebitstreams, comprising the steps of: (A) automating the specification toinclude automation for any combination of (i) corrupt fields in profile,(ii) corrupt fields not in profile, (iii) corrupt legal fields inchecking report, (iv) corrupt illegal fields in checking report, (v)corrupt fields in coverage report, (vi) corrupt fields not in coveragereport, (vii) corrupt fields not in profile and not in coverage report,(viii) corrupt fields not in profile and illegal fields in checkingreport, (ix) corrupt fields not in profile, illegal field in checkingreport and not in coverage report, (x) corrupt illegal fields inchecking report and not in coverage report, (xi) corrupt all fields inprofile, checking and coverage reports, (xii) corrupt start code fieldin profile at 16/1, rest of header syntax at 16/4 and all data payloadat 64/32, (xiii) corrupt fields not in coverage report with start codefield in profile at 10/1, rest of header syntax at 10/3 and all payloadat 64/64, (xiv) corrupt fields in profile at 64/8, except for illegalfields in checking report which should be at 32/4; (B) receiving theavailable parameters on a bitstream from the profiling, checking, orcoverage information; and (C) building sets of bitstream specificationsbased on automation specifications and available parameters.
 17. Themethod according to claim 16, wherein a desired level of corruption inspecific field in the profile can be specified.
 18. The method accordingto claim 16, wherein said system is used to generate sets of corruptedbitstreams.
 19. The method according to claim 16, wherein the profilingof the bitstream, representing field fragmentation, is used to automatethe corrupt bitstream generation by specifying parameters.
 20. Themethod according to claim 16, wherein the checking of the bitstream,representing what fields and bits are illegal, is used to automate thecorrupt bitstream generation by specifying parameters.
 21. The methodaccording to claim 16, wherein the coverage of the bitstream,representing what field and bit permutations have not been used, is usedto automate the corrupt bitstream generation by specifying parameters.22. The method according to claim 16, wherein the profiling, checkingand coverage information used for automation can represent multiplebitstreams.
 23. The method according to claim 7, used in a system thatautomates compact bitstream generation for existing bitstreamscomprising the steps: (A) reviewing the profiles of the existingbitstreams; (B) developing a single profile based on the bitstreamprofile reviews that would represent a significant compaction; (C)generating a bitstream based on the single profile; (D) checking thegenerated bitstream to ensure compliance and coverage goals have beenmet, otherwise refining the profile; and (E) optionally ignoring thedata size and value to reduce the size of the bitstream.
 24. The methodaccording to claim 7, used in a system that automates compact bitstreamgeneration for verification of field(s), comprising the steps of:specifying the field in the same manner as represented in the profile;reviewing the profiles of the existing bitstreams; copying a singleprofile from an existing profile and edited the existing profile to addthe field coverage; generating a bitstream based on the single profile;and checking the generated bitstream to ensure compliance and coveragegoals have been met, otherwise refining the profile.
 25. The methodaccording to claim 7, used in a system that automates compact bitstreamgeneration for comprehensive coverage comprising the steps: reviewingthe profiles of the existing bitstreams; copying a single profile froman existing profile and editing the profile to add full coverage;generating a bitstream based on the single profile; and checking thegenerated bitstream to ensure compliance and coverage goals have beenmet, otherwise refining the profile.